Discouragement, conquering of, xi, 337-40 (see also Dejection, Despondency) Discoveries, accidental, xv, 212-13, 232, 241-2; great, usual way of, x, 40; priority in scientific, 122 Disease Germs, x, 193-226, xiii, 71; body resistance to, ix, 177-9, 185-7, x, 197-8, 203-12, xi, 34; campaign against, x, 285-315; discovery of, x, 194, 381, xvi, 143; identification of, x, 150, 215-17; in air, danger from, i, 325-6; in sewage, viii, 326, 328; in water supplies, 41, 318, 319; man's struggle with, xv, 25-6; "portals of entry," x, 198, 201-2. (See also Infectious Diseases) Diseases, anciently ascribed to spirits, x, 12; atmospheric electricity and, i, 330; "atom" theory of, x, 26; Brunonian theory of, 89; causes and factors other than infection, 227-81, 283; causes of infectious, 193-226; causes of, historical conceptions, 380; climatic treatment, i, 331, x, 383; diagnosis, (see Diagnosis); electric treatment (see Electro-therapeutics); habit in, xi, 248; Hoffmann's nervous fluid theory, x, 85-6; Humoral Doctrine of, 21; hypnotic treatment, xi, 319; infectious (see Infectious Diseases); James on, x, 244; lesion differentiated from, 98; living causes, 193-226; Locke on curing of, 75; manifestations of, in organs, 318-65; mechanical theory of, 23, 70, 71; mental, 354-65; mental factors in, 242-4; metabolism, effects of, ix, 179, 302-4; nature in cure of, x, 21, 73, 75-6, 84-5, 367; occupational, 244-6; Paracelsus on causes of, 48-9; pneumatic theory, 26-7, 29; prevention of, 282-317, xv, 49; Pythagorean theory of, x, 18; racial susceptibility to, xv, 47-52; recognition of, x, 366-76; savage conceptions and treatment, xv, 352-3, 359; solidistic theory, x, 25-6; specific, 196; sthenic and asthenic, 89; spread by tainted water, xiv, 140; suppressed emotions and, xi, 140, 141; Sydenham on meaning of, x, 73; Sylvius's chemical theory of, 69; thirst unimpaired in, ix, 89; treatment of, x, 379-84 (see also Therapy); tropical, xiv, 356-7, xv, 49-50; Van Helmont's conception of, x, 68; (see also Disease Germs) Disgust, in various sentiments, xi, 146, 148 Disinfectants, viii, 332-3; chlorine, 86, 274, 333; formaldehyde, 219, 333; hydrogen peroxide, viii, 41; mercuric, 170, 333; ozone, vii, 354; sulphur dioxide, viii, 78, 333 Dismal Swamp, coal-forming conditions in, iii, 199 Displacement Currents, vi, 302, 305 Display Lighting, vi, 280, vii, 339-43; colors in, iv, 51; psychology of, xi, 344, 345, 346 Dispositions, sour and sunny, xi, 55 Dissection of human bodies, x, 30, 41-2, 45, 81 Dissociation, chemical, viii, 120, 121, 122, 375 Dissociation of Ideas, xi, 206, 209; in mental troubles, x, 355, 360-1, 365